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cartridge output level

Hi all,
This is Marco from Italy, I have a question about how a cart output level relates to volume knob position.

Let me explain: my VdH colibri is rated .45mv@5.7cm/sec, it goes into the mc phono stage of an hovland hp100 tube preamp, no complaints for the sound but the preamp volume knob is often in the 3 o'clock position, and anything below 12 is not enough.

Now this preamp phono stage is quiet enough up to 1 o'clock, above that the tube noise is audible, not to a level to ruin the listening pleasure, but is there.

I would like to be able to play with the volume knob between 10 and 2, the question is, if i could get a new cart, how do I know the correct output level to achieve that goal? I wouldn't want to end up not being able to go beyond 9 o'clock either.

Also, is there a difference in output level at 5.7cm/sec as per VdH spec compared to 5cm/sec of other manufacturers?

I know the simple answer is to try other carts in my setup, but unfortunately that is not an option here.

Any advice for a suitable cart is very much appreciated, I listen to jazz 60%, classical 30%, pop/rock 10%, I like lively dynamic sound with huge soundstage but not dry or too bright.

Thank you all,
Marco
cptaz
cptaz's avatar
cptaz OP
29 posts
 
Hi Hdm, the Hovland MC stage has a fixed impedance loading of approximately 530 ohm due to the built-in step-up transformers, as per instruction manual, with a "provision for reduced loading" by inserting resistors inside, but being the Colibri recommended load 500 ohm I thought that wouldn't be an issue.
Anyway, as I said before, I have no complaints for the sound quality, just for the quantity, I even thought to have Van den Hul increase the output, or trade in for the 0.65mv one, but I'm not sure that would fix the problem.
Do you think that reducing impedance loading would somehow increase the output level? I'm not much into tech stuff, I thought that would just affect tonality and/or frequency response.
viridian's avatar
viridian
4,184 posts
 
Marco, it's really a pickle, 63db of gain is more than enough gain for a cartridge of that output. The line stage gain of 14db is on the high side for a modern design as well. It would not seem that you should need to advance the gain control to 3 o'clock. Are you absolutely sure that the built in SUT is actually in the circuit? Lower impedance loading would give you less, not more output, so this is probably not the answer either. It may be time to drop Hovland an e-mail and see if they have any insight.
cptaz's avatar
cptaz OP
29 posts
 
Hi Viridian, whoa, the SUT NOT in the circuit? That doesn't sound good!!!
I just opened the Hovland, the input phonos on the rear panel are directly plugged into a metal box with a writing that says "HOVLAND MC7 high gain phono stage", from there a cable goes into the circuit board that has the tubes for the phono stage, maybe that box is empty and i was charged for the SUTs anyway. Well, I guess if such a thing can happen, it would happen here to me. It's definitely time for that e-mail to Hovland, thanks for the suggestion, I'll report back asap.
rlawry
414 posts
 
The overall gain of your system is what is really most important. With a 0.45 mV cartridge output, I don't think your 46 dB phono and 14 dB linestage gain are enough. You also need to know the voltage gain of your power amp and the voltage sensitivity of your speakers. You can actually figure out how much overall gain you need since most power amps need about 2 volts input to drive them to full power. Each 20 dB of voltage gain multiplies the voltage by a factor of 10. So if your overall phono and preamp gain is 60 db, you are multiplying your 0.45 mV by 1000 to give you 0.45 volts, not enough to drive your power amp IMO. Changing the impedance load won't affect the gain much if at all. I would see what Hovland has to say--if they cannot increase the phono stage gain I would look for an outboard unit. My Aesthetix Rhea has all-tube gain and goes up to 75 dB but I run mine at 62 dB. Again, you have a great cartridge, so I would be a lot more inclined to find a way to increase gain rather than changing cartridges.
viridian's avatar
viridian
4,184 posts
 
Rlawry, I think that you are reading the gain of the preamp incorrectly, he is getting 46db from the phono, 17db from the transformer (total phono gain 63db) and an additional 14db from the linestage, for a total preamp gain through the phono input of 77db. Plenty of output to drive the power amp with this cartridge, I shoud think.
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